1. Field of the Invention
The present invention relates to the field of contact lens care. More particularly, this invention relates to compositions for cleaning contact lenses which comprise a carboxy vinyl polymer which forms an abrasive precipitate when the compositions are rubbed on contact lenses.
2. Discussion of Related Art
The cleaning of human-worn contact lenses is a problem which has been addressed in numerous prior art patents and other publications. Many of the previous attempts to solve this problem have focused on the use of particular types of surfactants; the following patents represent examples of such attempts: U.S. Pat. Nos. 3,882,036; 3,954,644; 4,046,706; and 4,599,195. The use of enzymes has also been proposed as a solution to this problem; U.S. Pat. Nos. 3,910,296; 3,954,965; 4,096,870; 4,521,254; and 4,609,493 describe this approach. A relatively recent approach addressing the cleaning problem utilizes polymeric particles as an abrasive material to physically remove deposits from the surface of the lens; this approach, which has been relatively successful, is described in U.S. Pat. No. 4,493,783. U.S. Pat. Nos. 4,394,179 and 4,534,878 describe approaches wherein inorganic abrasive materials are utilized. U.S. Pat. No. 4,533,399 describes the use of a fibrous web to clean contact lenses.
There have been numerous other attempts to solve the cleaning problem in addition to those cited above. The following U.S. Pats. may be referred to for additional background information in this regard: U.S. Pat. Nos. 4,127,423; 4,357,173; 4,421,665; 4,440,662; 4,500,441; and 4,504,405.
A new approach to the cleaning problem is described in the copending and commonly assigned application of Van Duzee titled "CONTACT LENS CLEANING PRODUCT AND METHOD OF USE." This approach is based on the use of a nonwoven web impregnated with an enzyme to clean contact lenses.
Another new approach is described in the copending and commonly assigned application of Bhatia, et al., titled "CONTACT LENS CLEANING COMPOSITION AND METHOD OF USE." This approach is based on the use of compositions comprising an enzyme and an abrasive particulate material to clean contact lenses.
Yet another new approach is described in applicant's copending and commonly assigned application titled "CONTACT LENS CLEANING COMPOSITIONS CONTAINING AN ENZYME AND A CARBOXY VINYL POLYMER." This approach is similar to the approach taken in the present invention, but differs in that it is based on the use of a carboxy vinyl polymer in combination with an enzyme.